1. Field of the Invention
The present invention relates to a box nailing machine used for driving connected nails.
2. Background Art
In a box nailing machine in which connected nails extending in the longitudinal direction in a straight line are used, a magazine into which nails are charged is made by means of extrusion molding of aluminum, and a forward end portion of the magazine is fixed to a driving port from which nails are driven and a portion except for the forward end portion is fixed to a handle through an attaching arm. This structure is disclosed, for example, in JP-A-2002-273669. However, in order to manufacture the magazine at a low cost, it is considered to manufacture the magazine by means of press forming a metallic plate such as a steel plate. A box nailing machine having a magazine, which is press-formed in this way, is shown in FIGS. 1 to 4.
As described above, when the magazine 5 is attached to the handle portion 3, it is attached through the handle arm 4. As a method of attaching the magazine 5, which has been formed by means of press forming, to the handle arm 4, there are provided the following methods.                (1) Method of fixing by welding or calking as shown in FIGS. 1 and 2.        (2) Method of fixing by means of bolts as shown in FIGS. 3 and 4.        
However, in the case of item (1) in which fixing is executed by welding or the like, the following problems maybe encountered. When the box nailing machine is used over a long period of time, there is a possibility that the handle arm 4 is broken by a shock given in the case of driving nails. In the case of repairing the broken handle arm 4, since the handle arm 4 and the magazine 5 are welded to each other, the handle arm 4 must be replaced together with the magazine 5, which increases the repairing cost. In the case of item (2) in which the magazine 5 is fixed by bolts 7, the following problems may be encountered. Although it is common that the washer 9 is interposed between the bolt 7 and the attaching portion of the magazine 5 so that the magazine 5 can be fixed, in the case of a box nailing machine having a large magazine 5, the magazine 5 is fixed to the handle arm 4 by a plurality of bolts 7 for supporting the magazine 5. Therefore, when a plurality of washers 9 necessary for the plurality of bolts 7 are used as shown in FIGS. 5 and 6, the assembling efficiency is deteriorated. Therefore, it is considered to use one plate 10 as shown in FIG. 7. However, in order to insert the plate 10 into the magazine 5 in the process of assembling the magazine 5 to the handle arm 4, it is necessary to form a hole 13 for inserting the plate 10 into the magazine 5. The size of the hole 13, into which the plate 10 can be inserted, is so large that the mechanical strength of the magazine 5, which is formed by press forming a metallic plate such as a steel plate, is lowered.